首先写一个应用服务器端的jsp程序,用jsp和servlet简单实现,如下图所示
package cn.roco.domain; public class News { private Integer id; private String title; private Integer timelength; public News() { } public News(Integer id, String title, Integer timelength) { this.id = id; this.title = title; this.timelength = timelength; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public Integer getTimelength() { return timelength; } public void setTimelength(Integer timelength) { this.timelength = timelength; } }
package cn.roco.service; import java.util.List; import cn.roco.domain.News; public interface VideoNewsService { /** * 获取最新视频资讯 * @return */ public List<News> getLastNews(); }
package cn.roco.service.impl; import java.util.ArrayList; import java.util.List; import cn.roco.domain.News; import cn.roco.service.VideoNewsService; public class VideoNewsServiceBean implements VideoNewsService{ /** * 模拟从服务器中获取数据 返回 */ public List<News> getLastNews(){ List<News> newses=new ArrayList<News>(); for (int i = 1; i < 30; i++) { newses.add(new News(i,"Xili"+i,i+90)); } return newses; } }
package cn.roco.servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import cn.roco.domain.News; import cn.roco.service.VideoNewsService; import cn.roco.service.impl.VideoNewsServiceBean; public class ListServlet extends HttpServlet { private VideoNewsService newsService=new VideoNewsServiceBean(); protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { List<News> videos=newsService.getLastNews(); String format=req.getParameter("format"); //返回JSON格式 if ("json".equals(format)) { StringBuilder builder=new StringBuilder(); builder.append('['); for (News news : videos) { builder.append('{'); builder.append("id:").append(news.getId()).append(','); //转义 ""双引号 builder.append("title:\"").append(news.getTitle()).append("\","); builder.append("timelength:").append(news.getTimelength()); builder.append("},"); } builder.deleteCharAt(builder.length()-1);//去掉最后的',' builder.append(']'); req.setAttribute("json", builder.toString()); req.getRequestDispatcher("/WEB-INF/page/jsonvideonews.jsp").forward(req, resp); }else{ //返回XML格式 req.setAttribute("videos", videos); req.getRequestDispatcher("/WEB-INF/page/videonews.jsp").forward(req, resp); } } protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doGet(req, resp); } }
如果要返回XML文件 就forward到videonews.jsp页面
<%@ page language="java" contentType="text/xml; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><?xml version="1.0" encoding="UTF-8"?> <videonews> <c:forEach items="${videos}" var="video"> <news id="${video.id}"> <title>${video.title}</title> <timelength>${video.timelength}</timelength> </news> </c:forEach> </videonews>
如果要返回XML文件 就forward到videonews.jsp页面 如果要返回JSON文件 就forward到jsonvideonews.jsp页面
<%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%> ${json}
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>ListServlet</servlet-name> <servlet-class>cn.roco.servlet.ListServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>ListServlet</servlet-name> <url-pattern>/ListServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
服务器端写好之后,就开始写Android应用
架构如下图所示:
package cn.roco.news.domain; public class News { private Integer id; private String title; private Integer timelength; public News() { } public News(Integer id, String title, Integer timelength) { this.id = id; this.title = title; this.timelength = timelength; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public Integer getTimelength() { return timelength; } public void setTimelength(Integer timelength) { this.timelength = timelength; } }
package cn.roco.utils; import java.io.ByteArrayOutputStream; import java.io.InputStream; public class StremTools { /** * 读取输入流中的数据 * @param inputStream 输入流 * @return 二进制的流数据 * @throws Exception */ public static byte[] read(InputStream inputStream) throws Exception { ByteArrayOutputStream outputStream=new ByteArrayOutputStream(); byte[] buffer=new byte[1024]; int length=0; while((length=inputStream.read(buffer))!=-1){ outputStream.write(buffer,0,length); } inputStream.close(); return outputStream.toByteArray(); } }
package cn.roco.news.service; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL; import java.util.ArrayList; import java.util.List; import org.json.JSONArray; import org.json.JSONObject; import org.xmlpull.v1.XmlPullParser; import android.util.Xml; import cn.roco.news.domain.News; import cn.roco.utils.StremTools; public class VideoNewsService { /** * 获取最新的视频资讯 * 采用JSON格式 * @param path * @return * @throws Exception */ public static List<News> getJSONLastNews(String path) throws Exception { URL url = new URL(path); HttpURLConnection connection = (HttpURLConnection) url.openConnection();// 基于HTTP协议连接对象 connection.setConnectTimeout(5000); connection.setRequestMethod("GET"); if (connection.getResponseCode() == 200) { InputStream inputStream = connection.getInputStream(); return parseJSON(inputStream); }else{ throw new RuntimeException("服务器响应失败"); } } /** * 解析服务器返回的JSON数据 * * @param inputStream * @return * @throws Exception */ private static List<News> parseJSON(InputStream inputStream) throws Exception { List<News> newses=new ArrayList<News>(); byte[] data=StremTools.read(inputStream); String jsonData=new String(data,"UTF-8"); JSONArray array=new JSONArray(jsonData); for (int i = 0; i < array.length(); i++) { JSONObject jsonObject= array.getJSONObject(i); News news=new News( jsonObject.getInt("id"), jsonObject.getString("title"),jsonObject.getInt("timelength")); newses.add(news); } return newses; } /** * 获取最新的视频资讯 * 采用XML格式 * @param path * @return * @throws Exception */ public static List<News> getLastNews(String path) throws Exception { URL url = new URL(path); HttpURLConnection connection = (HttpURLConnection) url.openConnection();// 基于HTTP协议连接对象 connection.setConnectTimeout(5000); connection.setRequestMethod("GET"); if (connection.getResponseCode() == 200) { InputStream inputStream = connection.getInputStream(); return parseXML(inputStream); } return null; } /** * 解析服务器返回的XML数据 * * @param inputStream * @return */ private static List<News> parseXML(InputStream inputStream) throws Exception { List<News> newses = new ArrayList<News>(); News news = null; XmlPullParser parser = Xml.newPullParser(); parser.setInput(inputStream, "UTF-8"); int event = parser.getEventType(); while (event != XmlPullParser.END_DOCUMENT) { switch (event) { case XmlPullParser.START_TAG: if ("news".equals(parser.getName())) { int id = new Integer(parser.getAttributeValue(0)); news = new News(); news.setId(id); } else if ("title".equals(parser.getName())) { news.setTitle(parser.nextText()); } else if ("timelength".equals(parser.getName())) { news.setTimelength(new Integer(parser.nextText())); } break; case XmlPullParser.END_TAG: if ("news".equals(parser.getName())) { newses.add(news); news = null; } break; } event = parser.next(); } return newses; } }
package cn.roco.news; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import cn.roco.news.domain.News; import cn.roco.news.service.VideoNewsService; import android.app.Activity; import android.os.Bundle; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.Toast; public class MainActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); ListView listView = (ListView) findViewById(R.id.listView); try { //采用XML格式 // String xmlPath="http://192.168.15.58:8080/Hello/ListServlet"; // List<News> videos = VideoNewsService.getLastNews(); //采用JSON格式 String jsonPath="http://192.168.15.58:8080/Hello/ListServlet?format=json"; List<News> videos = VideoNewsService.getJSONLastNews(jsonPath); List<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>(); for (News news : videos) { HashMap<String, Object> item = new HashMap<String, Object>(); item.put("id", news.getId()); item.put("title", news.getTitle()); item.put( "timelength", getResources().getString(R.string.timelength) + news.getTimelength() + getResources().getString(R.string.min)); data.add(item); } SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.item, new String[] { "title", "timelength" }, new int[] { R.id.title, R.id.timelength }); listView.setAdapter(adapter); } catch (Exception e) { Toast.makeText(getApplicationContext(), "有错", 1); e.printStackTrace(); } } }
item.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/title" android:layout_width="200dp" android:layout_height="wrap_content"/> <TextView android:id="@+id/timelength" android:layout_width="fill_parent" android:layout_height="wrap_content"/> </LinearLayout>
main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <LinearLayout android:orientation="horizontal" android:layout_width="wrap_content" android:layout_height="wrap_content"> <TextView android:text="@string/title" android:layout_width="200dp" android:layout_height="wrap_content" /> <TextView android:text="@string/details" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> <ListView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/listView" /> </LinearLayout>
string.xml
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello World, MainActivity!</string> <string name="app_name">视频资讯</string> <string name="timelength">时长:</string> <string name="min">分钟</string> <string name="title">标题</string> <string name="details">详情</string> </resources>
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="cn.roco.news" android:versionCode="1" android:versionName="1.0"> <uses-sdk android:minSdkVersion="8" /> <!-- 访问Internet权限 --> <uses-permission android:name="android.permission.INTERNET"/> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".MainActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
运行效果如图所示:
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作者:欧阳鹏 欢迎转载,与人分享是进步的源泉!
转载请保留原文地址:http://blog.csdn.net/ouyang_peng
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